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W. G. LOOKWOOD. Gall Attachment for Telephones.

No. 233,526. Patented Oct. 19', I880.

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UNITED STATES WILLIAM G. LOOKWOOD, OF CHICAGO, ILLINOIS, ASSIGNOR TOLOGKWOOD TELEPHONE COMPANY, OF SAME PLACE.

CALL ATTACHMENT FOR TELEPHONES.

SPECIFICATION forming part of Letters Patent No. 233,526, dated October19, 1880.

Application filed April 24, 1880.

To all whom it may concern Be it known that I, WILLIAM G. LOOKWOOD, acitizen of the United States, residing at Chicago,in the State ofIllinois, haveinvented certain new and useful Improvements in Telephonesand in Electric Calls for Telephones, of which the following is aspecification.

My invention relates to speaking-telephones and electric calls for thesame; and the object is to combine the telephone and the call in oneinstrument having a compartment for the tele phone and a compartment forthe call device, arranged compactly together and both operated by asingle current of electricity, the circuit being successively broken andclosed to operate the call, and the instrument being ready for speakingor hearing through when the circuit is closed.

The call device separately from the telephone is a new device. Itconsists of an open-tongued diaphragm loosely arranged in a sonorous cupperforated to permit the escape of sound in connection with anelectro-magnet in such cup. As the circuitis successively broken andclosed, the electro-magnet operates the tongue and open, diaphragm,causing them to vibrate to produce the call-sound. The sound resemblesthe clicking sound of the ordinary telegraphinstrument, but is louder,being produced on 0 the same principle, but by devices in combinationwith the electromagnet materially different from those which produce thesound in the telegraph-instrument, and better adapted to produce sound.These devices, in combi- 3 5 nation with the electro-ma-gnet arranged inthe cup, and the same combined with the telephone-cup, are illustratedin the accompanying drawings,in which Figure 1 is a longitudinal centralsection of such combined instrument. Fig. 2 is a front view of thecall-cup, showingits perforations; and Fig. 3 is a reverse view of thesame cup, showing a side view of the call-diaphragm and its tongue.

Similar letters of reference refer to similar parts throughout theseveral views.

A is the telephone-cup, with a single coil, a, and electro-magnet a, ofsoft iron, under the (No model.)

diaphragm B, all constructed and arranged in the usual form.

C is the call-cup having a single coil and electro magnet, o of softiron, (the magnet being the opposite end of magnet a,) approachand issprung out at the end opposite to that secured to the diaphragm in themanner shown in Fig. 1. This tongue is made of thin sheetiron the samethickness as the diaphragm, or thereabout. The diaphragm is secured tothe perforated end or bottom of cup 0 by a screw, 6, passing looselythrough the tongue and diaphragm into the cup at one side, the otherside of the diaphragm being left free to vibrate against the adjacentperforated part of the cup. The tongue is brought so near the end of theelectro-magnet that the closing of the circuit will cause the tongue tobe drawn against the magnet, and by the breaking of the circuit the samewill be released and will spring back against the diaphragm, which islikewise, but to a more limited extent,made to vibrate against theadjacent end of the cup.

The magnet-bar is supported and held in position by a partition, F,which separates the telephone-cup A from thecall-cup O. Screws or pegsf, ofthe usual construction, are used to make the wire connections withthe instrument, and the current may be made to pass into the instrumentat either end, and should pass around or upon the coil first reached inits path, thence to the coilin the opposite cup of the instrument, andthence upon this coil and out to the earth.

If it is desired to increase the power of the instrument by using twoelectromagnets under each diaphragm in connection with alocal bat tery,this may be done by making the bar a, a with two prongs at each end,being in the shape of two Us with their bases turned toward each other,and connected bya short bar supported on the partition F, thus bringingthe bases of the Us against the partition and projecting their pron gstoward the diaphragms,

respectively. When so constructed the outer end of the coil upon one ofthe spools in cup 0 should be connected with the main line, and theinner end of the same coil should be connected with the outer end of thecoil on the spool in cup A, on the same side of the instrument-supposingthe prongs otthe double U- shaped bar, before described, to be all inthe same planeand the inner end of the wire on the last-named spool withthe zinc pole of the local battery, and theinner end of the other coilin cup A should be connected With the copper pole of the local batteryand the outer end With the inner end of the coil alongside of thefirstnamed coil in cup 0, and the outer end of the coil last namedshould be connected with the earth-line. With the four spools or coilson the four prongs of the double U-shaped soft iron bar having theirends of Wire thus connected the current will pass from the main line tothe first-named coil in cup 0, thence to the coil first named in cup Aon the same side of the instrument, thence to the local battery, thenceto the other spool in cup A, thence to the last coil in cup 0, andthence to the earth.

Any of the known Ways of alternately breaking and closingthecirouit atthe end ofthemain line or elsewhere may be employed to produce the call.I have successfully produced it by simply detaching the main line fromits connecting-post f on the instrument and rapidly tapping the postwith the metal connectingplug on the end of the line in my hand.

Having thus described my invention, what I clainn, and desire to secureby Letters Patent, is-

A telephone-call consisting of a diaphragm, E, having a tongue, D, in acup, 0, in combination with an electro-magnet, substantially as and forthe purpose specified.

WILLIAM (J. LOOKWOOD.

Witnesses:

JNo. H. WHIPPLE, JAMES C. HOLLAND.

